In my opinion, McIntyre and colleagues have misunderstood the primary point I raised in my earlier article in the Journal.1 My concern was not the increased number of women diagnosed with gestational diabetes mellitus (GDM), but the accuracy of the diagnostic thresholds. Although I suggested that many women in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study with one elevated blood glucose level may not be at risk, I also stated that additional women with two or more blood glucose levels marginally below the new thresholds will be at risk. The authors’ comment that an increased odds ratio has the same effect confirms that they misunderstood my concern.

My concerns about the combined primary end point were valid and I acknowledge the response provided — but is cord C-peptide > 90th centile a true adverse neonatal outcome?

I agree that thresholds should be determined by fully adjusted models.

However, no data have been provided to refute the assertion that many women with only one elevated blood glucose level may not be at risk. Each blood glucose threshold has been determined independently and not adjusted for normal blood glucose levels.2 The thresholds should accurately define patients at risk in the HAPO study,3 so the number of women diagnosed should approximate the total number of cases…